A conventional multi-layer ceramic capacitor (MLCC) includes a plurality of metal layers and a plurality of dielectric layers that are alternately disposed with the metal layers. Generally, the capacitance of the MLCC is increased with a decrease of dielectric layer thickness and an increase of number of dielectric layers.
A conventional method of making a dielectric layer involves a step of sintering a dielectric powder with ferroelectric or paraelectric property. A typical example of the dielectric powder with ferroelectric property is barium titanate powder.
In order to obtain a thinner dielectric layer, the barium titanate powder to be sintered is required to have a particle size that is as small as possible. However, the barium titanate powder with a small particle size has a tendency to aggregate or agglomerate into large particles, which hinders the formation of a thin dielectric layer.
In order to overcome the aforesaid problem, it has been proposed to use a core-shell powder having core-shell particles to make the dielectric layer. Each core-shell particle includes a conductive core body and a shell composed of a plurality of dielectric sub-particles attached to the conductive core body.
However, since the shell formed from the dielectric sub-particles has a loose structure, the capacitance constant of the shell of each core-shell particle is relatively low which is adverse for application to the MLCC.